<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            /* width: 200px;
            height: 200px; */
            background-color: pink;
            /* position: absolute;
            top: 50%;
            left: 50%;
            margin-top: -100px;
            margin-left: -100px; */
            display: inline-block;

        }
        body{
            margin: 0;
            /* display: flex;
            justify-content: center;
            align-items: center; */
            height: 100vh;
            display: table-cell;
            /* justify-content: center;
            align-items: center; */
            width: 100vw;
            text-align: center;


        }
    </style>
</head>
<body>
    <div class="box">哈哈哈哈哈哈哈哈哈哈</div>    
</body>

</html>